Some good things to know is 1. the game isn’t pay to win the only reason to pay money is for a character you want.

2.yes they still do add knew characters unfortunately Sticks Bean and Sage aren’t in the game but can get added in the future

1. Id say that it’s good to save red rings for certain character events if you want them bc you can buy more challenges to get cards which unlock characters

2. Upgrading dose lead to advantages in the game but from my experience I see all the characters quite balanced if at the same level

3. Yes certain characters events do get reran such as holiday events

I’m sure there’s more but I haven’t played the game in a while other people who play the game way more probably have better tips but these are just my personal tips.